They dream of the Red Planet as they lie sleeping in their Australian beds. The barren landscape reminds 44-year-old Dianne McGrath from Melbourne's South Bank of her childhood in the outback, growing up on an Aboriginal mission on the edge of the Simpson Desert. She remembers the extraordinary peace of being there.

In his dream world, 32-year-old Korum Ellis from Scarborough in Western Australia, calmly surveys the Martian sunrise, surrounded by mountains that can extend 21 kilometres into the thin atmosphere, and rock formations that have been moulded by aeons of alien weather systems. He marvels at the richness of the reds and ochres, infinitely more intense than those that saturate his native state.

They are just two Australians among 705 international applicants being considered for inclusion in Mars One, a privately run Dutch expedition, the goal of which is to begin populating Mars from the year 2024. In that year, a first ship of four astronauts will land on the planet; another five or six crews will follow.

Currently, 38 men and women from Australia and New Zealand are in the running to make a one-way, seven-month-long journey to an inhospitable planet no human has ever visited - an initiative conceived by a company that aims to generate the $US6 billion required to fund the mission by selling worldwide TV rights to what will be, in effect, the biggest reality-TV show ever. A suicide mission? Those involved don't think so.

Mars, the fourth planet from the sun, has long inspired intense curiosity as the only planet in our solar system to have a surface that's visible from Earth by telescope. (Venus is closer, but it's permanently shrouded in thick cloud.) Galileo first began to observe it in 1610, hoping to detect its different phases (these describe how the moon's appearance alters as it waxes and wanes) - something that wasn't possible if working within the then widely accepted confines of Aristotelian astronomy, which declared Earth to be the centre of the universe with perfect spheres rotating round it. Thousands of years of faith in humanity's place in creation were about to be overturned.

Jonathan Clarke, a geologist and associate member of the Australian Centre for Astrobiology at UNSW, is president of Mars Society Australia, the local chapter of a worldwide movement founded in 1998 to build public support for colonising the planet and to lobby for more government involvement in exploration programs. "Mars captured the imagination very early," he says. "In many respects, it's very Earth-like - a 24-hour day, more or less, and seasons, permanent surface features and weather."

In the 1951 science-fiction book The Martian Chronicles, American sci-fi author Ray Bradbury imagined Martians "painting pictures with chemical fire, swimming in the canals in the seasons when the wine trees filled them with green liquors". The poetry ended when the Mariner 4 spacecraft did a fly-by in 1965, coming as close as 9846 kilometres to the planet's surface, revealing a desolate, seemingly dead world with little atmosphere to shield against radiation and an average temperature of -55ºC, peaking during summer on the equator at 20ºC and falling to -153ºC at the poles. The gravity is 38 per cent that of Earth's, meaning an 80-kilogram person would weigh just 30 kilograms there.

"Mars has an atmosphere and a lot of water - mostly ice," says Clarke. "The technical view is that it would be easy to settle, [seeing as it has] water and gas and other raw materials. We'd be expanding humanity's presence in the universe, possibly creating new societies and escaping terrestrial problems."

Clarke wishes Mars One every success and says he'd go if someone was offering a round trip. "The chance to walk on another world, explore it and come back and talk about it? Absolutely," he says. But he wants to see more detail from Mars One. "The problem is they've released very few specifics, so it's very hard to technically assess. It's like talking to someone who says they're going to sail single-handedly around the world non-stop and the only thing they show you is a generic picture of a yacht."

Space flight used to be the province of government-funded bodies such as NASA, but the private sector is muscling in. Elon Musk, the billionaire founder of Tesla Motors (which released the world's first modern-era electric road car, the Roadster, in 2008) and space transport services company SpaceX, wants to send 80,000 people to colonise Mars, charging them $US500,000 each. Musk hopes to land people on Mars in 2020. "Either we spread Earth to other planets or we risk going extinct," he said at a Wall Street Journal conference in May. "An extinction event is inevitable and we're increasingly doing ourselves in."

Dutch entrepreneur and Mars One CEO Bas Lansdorp, 37, began working full-time on his own plan in 2011. He sold a majority interest in his start-up, Ampyx Power, a wind-energy technology company, to kick-start funding for the mission. He says the technology exists to fly

people to Mars safely and sustain life - the rockets, life-support system, living units, spacesuits and autonomous vehicles known as rovers - but estimates the cost of sending the first crew and sustaining the outpost to be about $US6 billion. US aerospace company Lockheed Martin will build the Mars lander, and the Paragon SpaceDevelopment Corporation will develop the life-support systems.

"No new inventions are needed for a mission of permanent Mars settlement," says Lansdorp. "But a human mission to Mars is hugely complex. We have a great team, the best suppliers and support from all over the world. We know that permanent settlement can be done and we are dedicated to making it happen."

In March last year he was quoted in The New York Times, saying: "How many people do you think would want to watch the first humans arrive on Mars? This will be one of the biggest events in human history."

Shortly before starting to assemble a team in February 2011, Lansdorp turned to fellow Dutchman Paul Römer, 51, co-creator of the Big Brother franchise and now a Mars One ambassador, who told him funding shouldn't be a problem if they created "the biggest media event in the world" around it. "Reality meets talent show with no ending and the whole world watching. Now there's a good pitch." The potential audience figures - and, therefore advertising revenue - are enormous: 94 per cent of Americans and an estimated 528 million people worldwide watched the Apollo 11 moon landing in 1969; the audience in 2024 for a Mars mission would be well in the billions. As for potential revenue, the International Olympic Committee generated $US3.9 billion from selling broadcast rights in the 2012 period.

Filming could start as early as this year when 20 regional selection rounds will be held to reduce the 705 contestants to the most suitable 100. (More than 202,000 would-be astronauts applied initially.) These will be supervised by Mars One's chief medical officer, Dr Norbert Kraft, a 51-year-old from Austria who has worked on space programs for the Austrian, Russian and Japanese governments, as well as Raye Kass, professor of applied human sciences at Canada's Concordia University, and the European Space Agency's James Kass.

Applicants will answer questions on a series of Mars-related topics, be invited to share their backstories, including the reactions of their families to their proposed adventure, and reveal their motivation: are they really passionate about wanting to go to Mars and embracing all the sacrifices such an odyssey will entail?

At the end of next year the number of candidates will be whittled down to 20 or 24. Each crew will comprise two men and two women. Kraft will help the crews choose each other with as international a mix as possible, to show how people from different cultures can learn to get along. He says, "They're making a new society by scratch on Mars, and I think this is beautiful."

In June, Mars One inked a deal with Darlow Smithson Productions, a company owned by TV production giant Endemol, to produce a show based on the selection and training of the candidates. Now they just have to sell it.

There promises to be no shortage of interesting viewing. Kraft spent 110 days in a Russian isolation unit in 2010 with would-be astronauts - the cramped setting revealing those mentally tough enough to survive on Mars. "The personalities come out very quickly in this closed environment where people are 24 hours together," says Kraft. "There's basically no escape."

I really like the idea of completely commercialising it and having it free of any government agenda," says Korum Ellis. "Selling this amazing story as it happens is a really modern way of doing things." Speaking to Good Weekend via Skype from WA, he's charming and with his wire-framed lozenge-shaped glasses, singlet, stubble and styled hair, looks as if he's just stepped off a fashion shoot that involves boats and woolly jumpers - as well he might: he's a model. He also acts, runs a micro-horticulture business and is a wellness coach.

"I've always had a deep excitement for the potential for discovery and pushing the boundaries of human endeavour," he says. "If it was 500 years ago, I'd be doing everything I could to get on the next expeditionary ship."

Ellis lived without electricity until he was 13. He grew up, off the grid, with his parents on the mid-north coast of NSW and watched them grow much of their food. They used kerosene lanterns or made candles and heated water in pots. "I wouldn't say they were Third World conditions, but they certainly weren't First World," says Ellis. "Let's say I have a pretty good understanding of how to make do for yourself with minimal input."

He says that, as a nature lover, the biggest thing he'll miss if he makes selection is the outdoors. "But the vistas of a new environment on Mars will certainly be mind-blowing enough to keep me interested."

He refuses to see the trip as a one-way mission, but rather as a migration. "Many people have left their country of origin and gone to a new land with the idea that they'll never return," he says. "There's a difference between sacrificing yourself on a suicide mission and making some personal sacrifices." He believes his experience in growing food in self-contained units will be useful, but admits that he feels out-qualified by most of the other candidates: 44-year-old German astrophysicist Robert Schwarz, for example, has spent the past 10 winters manning a radio telescope at the South Pole, while US-born Brent Bos, 44, is a research physicist at the NASA Goddard Space Flight Centre.

There's also "the entertainment factor, as silly as that might sound", he says. "I'm used to engaging with an audience and keeping them interested. A big part of the funding for the mission is selling the story and engaging an audience. They're going to need people who are great to watch and fun to interact with."

The five or six groups of trainee astronauts will be officially hired by Mars One next year at a salary to be determined. Then training will begin in earnest. In their groups, they'll spend three months of every year prior to lift-off cooped up in a Big Brother-like environment designed to simulate the living conditions they'll experience on Mars. A test building has been constructed in Denmark, but the site for the first working model has yet to be chosen. During this phase, they will be filmed constantly, both to provide footage for the show and to help researchers analyse their interactions. A further nine months of each year will include training in key specialist areas, such as medicine, dentistry, engineering, agriculture and exobiology - the field of alien life.

The psychological component of the training will be very tough. One test will be to enter a radiation shelter - "about the size of your kitchen or bathroom, very tiny", says Kraft - and stay there for two to three weeks, to mimic what you'd have to do in the event of a solar-flare emergency. "You have to do everything in this small confined room: you cannot go out to the toilet because you will get radiation. Can they survive this psychologically?"

As the would-be astronauts train - and any of them can be replaced at any point until their rocket leaves Earth - Mars One will prepare the site for habitation. The plan is to send a communications satellite into orbit around Mars in 2018 to enable transmissions between Earth and the Red Planet, followed by craft in 2020 and 2022 so that the site is operational by 2023 and habitable for the 2024 landing, with a new crew of four arriving every two years. Settlers will explore the surface, conduct experiments (is there native life on Mars?), carry out construction work and farming. The goal is to have the colony living independently as soon as possible. The site - expected to be located between 40 and 45 degrees latitude north - will be picked largely for the soil's water content. Before the first manned flight, this soil will be collected by a rover and heated until the water evaporates. Oxygen will be extracted from the water and power generated by the use of solar panels.

If all goes well, there will be a life-sustaining atmosphere inside the base, a modular environment of inflatable units, each one measuring 1000 cubic metres, equivalent to a cube 10 metres on each side. The settlers will begin growing food hydroponically as a priority. Mars One has yet to provide details, but Ellis suspects algaes are a possibility, since they're a potent aid for oxygen conversion and could feed a protein source, such as locusts and mealworms, along with salad greens, tomatoes and capsicums. There will be two years of food in reserve, similar to that on the International Space Station (ISS). (The ISS menu includes beef sirloin tips with mushrooms and ham baked with candied yams.)

The teams will spend the seven months travelling to Mars in less than 20 cubic metres of space each, the first group existing as sole settlers for two years, with each message transmitted to and from Earth expected to take at least 10 minutes. These men and women will need to be adaptable, says Kraft. "You know MacGyver? Think about four MacGyvers working as a team: 'How can I solve this problem?' 'How can I repair this machine?' Once they're on Mars, we can't help them."

At a Sydney CBD cafe I meet Sinui Pavino, 35, from Drummoyne, another of the 705 remaining applicants. He shows me a photo of an engineering project of his: a mechanical glove he's made that he plans to roboticise. Pavino's a fan of Iron Man, the cartoon superhero who invents a mechanical suit to augment his powers. (In June, the character's creator, Stan Lee, signed the glove at the Supanova Pop Culture Expo in Sydney.) He also shows me a video of a double-acting jackhammer he's built. "You'll only see it work for a second because I don't want to blow the fuse in the apartment," he says.

At 14, Pavino dropped out of high school to work in the Lightning Ridge opal fields. "I had to go to work, I had bills to pay," he says. "School wasn't working out too well, though it turns out I'm good at maths." Pavino has had various jobs, but is now studying for his tertiary preparation certificate - his "second chance" at a Higher School Certificate. His strengths are in repairs and mechanical assembly. "I can basically fix anything," he says. "Mars is a hostile environment. Everything has to work like clockwork." The idea of travelling to Mars inspires him. "I've always wanted to be part of a large-scale project like this. Up until now, I've only had grunt work and odd jobs. Having an opportunity like this - it's the ultimate."

His mother, Angela Pavino, says, "We're going to miss him, we wouldn't be human if we didn't. But this is his dream."

Applicant Dianne McGrath volunteered for two weeks in 2012 as a crew member on the Endeavour tall ship as it circumnavigated Australia, and it whetted her appetite for adventure. "Climbing 40-metre masts when the ship's rocking like this" - she see-saws her hands - "and the wind is gale force is pretty intense stuff. But when you're up there and doing it, you forget about all the stuff that almost stopped you. I like to push myself past the things that stop me."

McGrath, chic in a black-leather jacket and striped grey scarf, with a wedge haircut almost hiding her left eye, is a sustainability project management consultant with an interest in closed-loop food systems. She's also very fit, being a distance cyclist and runner. McGrath has been with her partner, Michele Bauer, for 11 years. "When I came home and said, 'I want to apply for this thing', Michele said, 'Of course you do. And you'll get in - of course you will' ... Her attitude is, 'We'll deal with what happens to us on the day you leave.' "

McGrath, says Bauer, has a habit of winning competitions she enters, whether it's a two-dollar Scratchie or a trip to the Whitsundays. She's got a gut feeling she'll make it all the way. "I'd absolutely miss her but, at the same time, she'd be doing something no one else has ever done before," she says. "That's amazing."

When Jake Sinclair, 19, from Sydney's Doonside, told his mum he'd applied to join Mars One, she replied, "Yeah, if they'll take you." Then he made the first cut to a group of 1056 and she "started freaking out - she didn't realise I was serious." Sometimes when he gives her a hug when he gets home, she says, "I'll miss these hugs when you're on Mars." He's dressed like any normal teenager - hoodie, T-shirt, sneakers and jeans - has floppy brown hair and is polite and articulate. Sinclair is studying contemporary music and is planning to transfer to a bachelor of arts with a major in media, technology and law.

He works at a local video-production company and also tours schools giving talks about robotics: he's worked on teams that have built robots that can play soccer, basketball, and throw a frisbee. He finds it easy to see how things work.

He's wanted to travel across the universe since he was young. "It feels very comfortable, very natural, picturing being out there on Mars," he says. "It'll be sad to never see the beach again, feel the waves, the sand, see the sunset, go on a train somewhere, but there are certain compromises you have to make if you want to do something like this."

The Mars One mission is not without its critics, including the General Authority of Islamic Affairs and Endowment, an organisation set up by the United Arab Emirates, which has issued a fatwa against Muslims taking part. "Such a one-way journey poses a real risk to life and that can never be justified in Islam," the committee said, according to the Dubai-based Khaleej Times.

Andy Thomas, Australia's first astronaut, who flew on a number of space shuttle missions, was part of a NASA team planning a round-trip to Mars in 2035 touchdown, until he retired last February. He calls Mars One "a marketing scheme, more a way of generating revenue. It's all hype and gloss and marketing. There's no light or substance behind it. It's certainly not based on any sound technical proposal."

Former German astronaut Ulrich Walter believes there's probably only a 30 per cent chance of Mars One astronauts reaching the planet alive and no more than a 20 per cent probability of them lasting there for more than three months. Professor Andrew Dempster, director of the Australian Centre for Space Engineering Research, believes - like Jonathan Clarke - that the technology to get people and equipment to Mars exists, but says, "There's not much to which we can compare the psychology of a one-way trip. They're not just living together, they're dying together."

Galactic cosmic radiation (GCR) - high-energy particles that originate in deep space and defy effective blocking - are a real concern, says Thomas, with settlers on Mars very likely to be exposed to severe doses of it as time passes. A 2013 University of Rochester study stated GCR could accelerate the onset of Alzheimer's disease. "Life expectancy will be severely reduced," Thomas says. To what extent is a good question: there's little research on the topic. Thomas says the real challenge lies in just getting to Mars.

Norbert Kraft, who is more bullish about a life on Mars, likes the idea of settling there with his wife when he retires. He says the planet's low gravity means the heart won't have to work as hard to pump blood around the body, and knee and back pain will be lessened. "Your wrinkles disappear, too," he says jovially. "It's an absolute youth farm." Settlers will, he insists, be shielded from radiation by a minimum five-metre-thick barricade of soil surrounding the base.

Defending the one-way nature of the trip, Kraft says returning to Earth is likely to be very dangerous due to the effect of long-term low-gravity living on bone density. The G-force the body must withstand on re-entry into Earth's atmosphere - two to three times the gravitational force we experience on the surface - would likely cause bones to crumble. You could spend all your time in a centrifuge to keep your bone density high, Kraft says, but then why be on Mars at all?

In April, Arthur Saniotis, from the University of Adelaide's School of Medical Sciences, was appointed adviser to the International Academy of Astronautics' study group on medical support for an international human expedition to Mars. He's interested in how long-term space travel will affect human physiology and psychology. Of the Mars One project, he says, "My basic problem is we're going to be away from the biosphere and from nature. We are animals and we have evolved in this particular domain.

"When we're divorced from nature there are going to be all kinds of problems going on. Our interaction with nature ... affects every aspect of our neuro-hormonal repertoire. When you go to a world where you don't have this sensory engagement, how will this inform our future evolution?"

So what's next? First up, selling the TV rights now the Endemol deal has been signed. Mars One won't say how much it has raised - it's seeking investors as well as TV money - but it's not missing any opportunity to fund-raise. To become a member of the Mars One web community, which will give you voting rights for what the website calls "several mission decisions in the future", one must donate money or buy a piece of merchandise. So far, public donations and purchases total more than $US570,000.

"Bear in mind 99 per cent of what viewers will see will look like housekeeping inside a tin can," says Clarke. Watch the ISS webcam, for instance, and you will see little in the way of death-defying stunts. "They're running experiments, fixing things, doing the cleaning," he says. In other words, if it's exciting, something has gone wrong. "It will be the opposite of Big Brother where contestants are chosen to fail," Clarke adds. "Here, safety has to come first. In Big Brother, you can leave. You can't walk out of Mars."

Indeed, selecting would-be astronauts on the basis that they might perform well on camera could backfire. US psychologist Suzanne Bell has studied how certain personality types fare within a space-travel environment. In June, she told a conference that extroverts can be too demanding. "Their level of warmth may be undesirable in a confined setting," she says. "You're talking about a very tiny vehicle where people are in a very isolated, confined space. Extroverts can have a little bit of a tough time in that situation."

While they would become instant global celebrities, our would-be Martians are driven by a sense of something greater than themselves. Jake Sinclair is inspired by the project's massive international scale - "not just the Americans or Russians sending humans up into outer space, but everyone, a collective, working together for a greater purpose". Korum Ellis says the moon landing of '69 inspired a whole generation to raise the bar on what is possible. "Imagine a child growing up 15 years from now with the mindset that humans are a dual-world species; that's where our horizons are right now."